People have directly transmitted information from one person to another. Information was first transmitted by spoken word and later by written word. Writings enabled people to transmit information by messengers from a location in which the sender of the writing was present to another location where the receiver was present. In time, postal services were developed in which a person would deliver a letter to the post office in one city, and an agent of the post office would deliver that letter to a post office in another city, where the letter would be picked up by the person to whom the letter was sent.
Ever since the numeric codification of streets and buildings received general acceptance, an individual's name and the individual's household postal address have been linked. The sender of a letter or package would deliver a letter or package to the post that had the correct recipient postal address, and the post would deliver the letter or package to the numeric street address of the recipient of the letter or package. A correct recipient postal address for the delivery of the letter or package to the recipient included the name of the recipient; the street address of the recipient; the city and state of the recipient; and the zip code of the recipient. Thus, the correct recipient postal address is usually the actual location of the recipient.
Sometimes senders of letters, flats and packages like to know where the recipient letters and packages are in the delivery stream. For instance, if someone is shipping goods, bills, documents, dated material, etc. to different areas, they may want to know if there are any problems delivering the letters, flats and/or packages. Someone may also want to speed up or slow down the delivery of a letter, flat or package that is in the delivery stream. The sender may want to redirect the letter, flat and/or package, because the recipient wants the letter, flat and/or package sent to a different address. The sender may want the letter, flat and/or package back because the recipient does not pay its bills, or the recipient is bankrupt. The sender may also want to make sure that the recipient can not divert the sending of the letter, flat and/or package to a different address; e.g., the letter, flat and/or package may contain legal documents.